The present invention relates to an optical lens package, in particular for LED light sources, said lens package having a lens body comprising a base, a central surface section opposite to the base and a peripheral surface section extending between the central surface section and the base, said central surface section being centered with respect to an optical axis of the lens package and having a convex shape in at least a first cross-sectional plane including the optical axis.
A main application field of the present invention is the field of automotive signal lighting. In automotive signal lighting many test scenarios require side visibility of the emitted light. This means, that at least in one cross-section of directional space, light has to be directed to high angles with respect to the central lighting direction or axis to provide visibility from e.g. −85° to 85°, whereas the central light bundle of high intensity values extends only from e.g. −20° to 20°, measured from the central axis. LED packages (LED: light emitting diode) are well known, which provide a good central light bundle for automotive signaling requirements, extending e.g. from −20° to 20° from the central axis.
Using automotive signaling LEDs with package optics, no additional separate optics is necessary to form a good legal bundle of light with a reasonable number of LEDs and moderate luminous flux. U.S. Pat. No. 7,993,035 B2 discloses an aspherical LED angular lens for narrow distribution patterns. This aspherical lens has a concave shape at the entrance side and a convex surface shape at the opposite side of the lens. By using such an aspherical shape the light emitted by the light source is collimated to achieve a narrow angular circle-distribution pattern which is greater than 15° and smaller than 30°. Such an optical lens package however does not fulfill side visibility requirements. Additional secondary optics is needed to divert light into directions far from the optical axis, e.g. extending up to +/−85°. The additional effort to provide side visibility optics can be significant thus increasing the costs of such an optical system.
US 2008/0239722 discloses a LED apparatus for illumination provided with a first lens positioned over the LED and a secondary lens surrounding the primary lens. The primary lens has a central axis. The secondary lens has a principal perimeter surface with a reference axis parallel to and at distance of the central axis. The principal perimeter surface projects downwardly and inwardly to a ridgeline. The ridgeline subtending a substantial angle about the central axis. Due to the principal perimeter surface, the apparatus for illumination has a preference side to which the light is directed in a laterally biased direction and little or no light is being directed toward the non-preferential sides.